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FUNDAMENTALS OF COMMUNICATION ENGINEERING
1. What do you mean by radio communication?
Ans. The process sending audio signal from a source to distant destination using carrier wave is called radio communication.
2. Explain communication system with the help of block diagram?
3.Wite name of sub units of radio communication system?
ii. Transmission Channel
4 What do you understand by modulation?
Ans. The process of varying one of the characteristics of a high frequency wave ai accordance with the instantaneous value of a low frequency signal is called modulation.
5 What is modulating wave?
Ans. Low frequency signal is called modulating wave.
6 What is carrier wave?
Ans. High frequency wave is called carrier wave.
7 What are different types of modulation?
Ans. i. Amplitude modulation (AM)
ii. Frequency Modulation (FM)
iii. Phase modulation (PM)
8 Give the definition of Amplitude modulation (AM)?
Ans . Amplitude modulation (AM) is a technique used in electronic communication, most commonly for transmitting information via a radio carrier wave. AM works by varying the strength of the transmitted signal in relation to the information being sent.
9 Give the definition of Frequency Modulation (FM).
Ans. Frequency modulation (FM) conveys information over a carrier wave by varying its instantaneous frequency in accordance with the frequency of the carrier wave.
10 What is modulation index?
Ans. Modulation index of amplitude modulation is defined as the ratio of the amplitude of the modulating wave to the amplitude of the carrier wave
11 what are the disadvantages of AM?
i. Smaller operating range
ii. Poor audio Quality
iii. Low Efficiency
12 What are the advantages of FM?
i. Noiseless Reception
ii. Better Quality
iii. High operating range
iv.Efficiency is very high
13. What are the disadvantages of FM?
Ans. i. Costly equipments
ii. Smaller area of reception iii.Much wider channel is required
14. What is demodulation?
Ans. The process of recovering the audio signal from modulated wave is known as demodulation. Or detection. Thus demodulation is reverse process of modulation .
15 Give the definition of phase modulation (PM)?
Ans. In this he phase of the carrier wave is varied in accordance with the instantaneous value of modulating signal.
16 What GSM and CDMA stands for?
Ans. GSM stands for Global system for mobile communication.
CDMA stands for Code division multiple access.
17 What do you understand by the term television.
Ans. Television (TV) is the most widely used telecommunication medium for transmitting and receiving moving images that are either monochromatic ("black and white") or color, usually accompanied by sound. "Television" may also refer specifically to a television set, television programming or television transmission.
18 Determine the size of antenna working at frequency of 20 kHz and wave length of wave 1.5*106 m given that velocity of light to be3*108 m/s .
Ans. λ = c/f
= 3*108 m/s/20*103 = 15*103 m
Size of antenna = λ/4 = 3750 m. ans.
19 What is super heterodyne radio receiver ?
Ans. It is an improved radio receiver which employs the principle of heterodyning (means frequency translation
20. What is the basic principle of communication satellites?
Ans. communication satellites has uplink and down link frequency and used for various research works and weather forecasting.
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